Nazanin Zaghari-Ratcliffe is about to leave Iran where she has been detained, the Reuters news agency has reported.

The British-Iranian mother was arrested in April 2016 as she prepared to fly back to the UK, having taken her daughter Gabriella – then not even two years old – to see relatives.

She was accused of plotting to overthrow the Iranian government and sentenced to five years in jail, spending four years in Tehran’s Evin Prison and one under house arrest.

Both the British Government and Mrs Zaghari-Ratcliffe have always denied the allegations.

While the details of the negotiations remain unclear, it is possible they are linked to a £400 million debt dating back to the 1970s owned to Iran by the UK.

Labour MP for Hampstead, where Nazanin's family live, Tulip Siddiq said: "Nazanin is at the airport in Tehran and on her way home.

"I came into politics to make a difference, and right now I’m feeling like I have."

The Prime Minister cautiously raised hopes on Wednesday that the dual national’s six-year ordeal could come to a close after suggestions the mother-of-one has had her passport returned.

Mrs Zaghari-Ratcliffe’s sister-in-law Rebecca Ratcliffe had said the family are trying not to raise their hopes too much.

She told BBC Breakfast: “This may all be over in a week or two. But also it may just be a stunt from the Iranians. We’ve had this before.

“We’ve had many ups over the last six years and been told she’s been about to be released. So there’s an element of false hopes and I think our family, Nazanin, her parents, find it hard to get too excited at the moment.”